SAAC Forum

The Cars => 1968 Shelby GT350/500/500KR => Topic started by: Michael Bol on June 04, 2023, 03:05:24 PM

Title: Which coil and ignitor-system 1968 Shelby GT350
Post by: Michael Bol on June 04, 2023, 03:05:24 PM
Want to now which coil and ignitor-system will be the best for my 1968 Shelby GT350.
The original points are gone. I do have an unknown electronic ignitor in the distributar but the original coil. The spark is very weak.
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Rickmustang on June 04, 2023, 03:43:31 PM
Petronix 1 is shown reliable. How do you know the spark is weak? Original yellow top coils are great.
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Michael Bol on June 04, 2023, 04:29:49 PM
The color of the spark is very yellow. The engine runs bad. Could be several things.
I thought that the ignition (like petronix) should match the coil.
And why not petronix III?
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Michael Bol on June 04, 2023, 04:37:39 PM
Clip: sounds not smooth- loses power and wants to stop.
Image: when it runs this comes out of the exhaust. Seems bad timing or to rich.
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Royce Peterson on June 04, 2023, 06:13:33 PM
It's normal for water to condense in the exhaust system. It happens every time the exhaust is heated. When it cools water vapor in the air condenses in the exhaust system. When you start the car it puts soot on the ground.

Your video was short but you need to start by setting the timing properly. Then take the car to a chassis dyno and have them connect a fuel / air meter to the exhaust pipe to tell what the mixture is doing. If the car runs likely the ignition system is working fine.
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: TA Coupe on June 04, 2023, 07:48:33 PM
"Pertronix" 3 has features that will you will never use unless you go Drag Racing so a 1 or 2 would be much better for you and I would go. With a two personally.

       Roy
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: shelbydoug on June 05, 2023, 10:45:36 AM
How about the stock points distributor and yellow top coil? A Boss 302 dual point works really well with a yellow top also.

Mine has the C8 distributor housing with a B2 dual point guts w/yellow top.

You can buy the MSD BS if you like but look at what was run in trans-am back in the day. Nothing has the durability of the original FORD components.

Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: CharlesTurner on June 05, 2023, 11:24:49 AM
Those petronix units usually work best with a lower ohm coil.  If I remember right, the Ford yellow top coil is around 1-2 ohms.  Electronic ignition coils are usually less than 1 ohm depending on the system.
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Bob Gaines on June 05, 2023, 01:19:52 PM
I am not sure if this is a cause for the engine running badly  but the pertronix can cause poor engine running symptoms if you have it connected to the stock resistor wire to the coil instead of the mfg required full 12V.  It needs a full 12V like the MFG insists. A very common mistake with pertronix. Can you confirm how you have the pertronix unit wire? Is the pertronix connected to the coil or it to someplace else?
Title: Re: Which coil and ignitor-system 1968 Shelby GT350
Post by: Michael Bol on June 05, 2023, 05:42:25 PM
I'll check. My thoughts as well.